1. Field of the Invention
The present invention relates to a terminal box for an optical fiber and power line composite cable, and more particularly, to a terminal box to which an optical fiber and power line composite cable including both optical fiber units and power line units is connected, and which is capable of minimizing an interference between the optical fiber units and the power line units when the optical fiber units and the power line units branch off from the optical fiber and power line composite cable and are pulled out of the terminal box.
2. Background Art
In the case of conventional mobile communications, a communication signal is transmitted to a base station from a backbone station of a telecommunication company or the like, and a radio-frequency (RF) signal is transmitted from a base transceiver station (BTS) of the base station via an antenna of the base station. A radio signal transmitted from a user's mobile phone is transmitted to the antenna of the base station, amplified through a tower mounted amplifier (TMA), and then supplied to the BTS. In this case, the base station, the TMA, and the antenna are connected via a coaxial feeder.
However, the longer the length of a cable, the greater signal loss in the coaxial feeder. When the antenna is installed at a tower having a height of several tens of meters, signal loss occurs in the coaxial feeder that connects the antenna and the base station installed on the ground. Since the signal loss occurring in the coaxial feeder causes a signal supplied from the base station to have an intensity that is less than signal intensity required in the antenna, the supplied signal attenuates. Thus, the supplied signal needs to be amplified by the degree to which the signal attenuates in the coaxial feeder, thereby causing additional power consumption. Also, since the intensity of a signal transmitted from a mobile phone to the antenna of the base station is relatively low, it is very difficult to transmit the signal to the BTS via the coaxial feeder causing high signal loss. Accordingly, it is necessary to install a TMA at an input unit of the antenna to amplify the attenuating signal. However, since the TMA consumes a relative large amount of power to amplify the signal, high costs are incurred to perform maintenance and repair, thereby lowering system efficiency.